I got a comment to this morning’s Hubble column from a “Steve Mickler” at the post announcing it. I thought it would be better to respond in a different post, because it gets into one small aspect of the column in much greater detail:

Just read your article in TCS and while its a fine piece of writing; I must take strong exception to your dismissal of telerobotic technology.

I wasn’t dismissing it in general–I was indicating skepticism for the purpose of this specific mission. A skepticism, for what it’s worth (if you’re into arguments from authority) that the National Academy of Sciences shares.

Firstly, using Skylab as a refutation of telerobots is bizarre and the relevance of the Solar Max repair mission is something of a stretch since it used old technology and did not include anything resembling the two armed, dual camera, anthropomorphic robot using 2000’s tech that was proposed. Since no comparable device has been tested on-orbit and given the absolute confidence expressed by the contractor based on ground tests, your conclusion seems premature.

My invocation of Skylab, and the other successful (some only by the skin of their teeth) repair missions was to point out that something almost always happens that’s unexpected, and difficult to anticipate enough to build in a telerobotic capability to handle it.

I have no doubt that the contractor has “absolute confidence” based on ground tests. So did the contractor who belatedly discovered that objects in zero gee don’t behave the same way that they do in a Weightless Environment Test Facility (because the viscosity of the water has effects that don’t occur in vacuum), or the contractor who designed the grappling mechanism that ended up not grappling the satellite. Such “absolute confidence,” in light of the history of space repair, goes beyond confidence, to hubris.

Also, development of telerobotics on-orbit is an enabling technology which can increase human mediated activity in space by orders of magnitude versus spacewalking astronauts. The flexibility of humans to respond to the unexpected is actually increased if a telerobot is their tool since it is able to do things that would be to risky for the human and since it can stay on station hundreds of times longer. Untill a hard shell type spacesuit with dextrous gloves is developed, humans will be severely limited vs. telerobots. With TR the number and variety of repair and reboost missions will greatly increase while the lead times and costs go way down.

I wrote nothing in my article to dispute this. I expressed no opinion on the general utility of continuing to advance telerobotics, and in fact am all in favor of it. I was simply pointing out that the chances of success in using it on Hubble were very low, in proportion to the costs, and the risks of screwing something up so that perhaps even a later crewed mission might not be able to fix it were non-zero. This is a useful technology, but not, in my opinion, one that’s ready for prime time on a critical system that was designed to be serviced by humans.

Admittedly there are many issues including the variable signal delay time to be solved but at the end of the day a new capability is developed not just a single repair accomplished.

Yes, and that’s not a trivial issue. It’s one of the things that makes the mission risky. I agree that if the mission is successful, it’s a huge step forward. I disagree that we should use a critical mission as a test for such a system, particularly given the high cost. Test it on ISS first. That’s one of the reasons that we supposedly built it.

Remember how long it took to get Hubble up there in the first place? Well that was done when the gov was in far better financial shape than now. I wouldn’t hold my breath.

Well, even if things go on schedule, I wouldn’t advise that…